Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: CAS:61191-21-7 (2-butanone)
 604 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The condensation of 3-hydroximino-2-butanone (1) with 5-amino-6-ribitylamino-2,4(1H,3H)-pyrimidinedione (2) yields 6,7-dimethyl-8-ribityllumazine (3). At slightly alkaline pH, the carbonyl group of 1 reacts preferentially with the 5-amino group of 2 (regioselectivity, 4:1). Under acidic conditions, the reaction occurs with higher yield and marginal regioselectivity of opposite direction (1:1.4). Appropriately 13C-labeled samples of 1 afford 3 labeled at C-6 alpha, C-6, C-7 or C-7 alpha. [6 alpha, 7 alpha-13C2]-3 was prepared by condensation of 2 with [1,4-13C2]diacetyl. The lumazines 3 were converted to riboflavin by the enzyme, riboflavin synthase, with almost quantitative yield. By this procedure, any C-atom of the carbocyclic moiety of riboflavin can be selectively labeled with 13C at high abundance. Phosphorylation yields the respectively 13C-labeled FMN samples.
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PMID:Enzymatic synthesis of riboflavin and FMN specifically labeled with 13C in the xylene ring. 295 89

The syntheses of 8-deazahomofolic acid and its tetrahydro derivative, potential inhibitors of thymidylate synthase (TS) and other folate related enzymes, are described. Wittig condensation of 2-acetamido-6-formyl-4-pyrimidinol with the triphenylphosphine ylide 3 derived from N-acetyl-4-(p-carbethoxyanilino)-1-chloro-2-butanone, hydrogenation of the enone intermediate 5, introduction of a 5-amino group via diazonium coupling, and reductive ring closure yielded ethyl N11-acetyl-8-deazahomopteroate (8). Alkaline hydrolysis gave 8-deazahomopteroic acid, which was blocked as the 11-trifluoroacetyl derivative, coupled with diethyl L-glutamate, and the blocking groups saponified to afford 8-deazahomofolic acid (12). Hydrogenation of the glutamate diester intermediate and subsequent saponification yielded the tetrahydro-8-deazahomofolate (14). Growth inhibition of Streptococcus faecium, Lactobacillus casei, and L1210 cells in culture by the target compounds was modest. They were also weak inhibitors of thymidylate synthase, dihydrofolate reductase, glycinamide-ribonucleotide transformylase, and aminoimidazolecarboxamide ribonucleotide transformylase. In contrast, 8-deazafolate showed moderate inhibition of aminoimidazolecarboxamide ribonucleotide transformylase, suggesting that inhibition of this enzyme may be related to its cytotoxic action. Tetrahydro-8-deazahomofolate showed low substrate activity with thymidylate synthase.
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PMID:Synthesis and biological evaluation of 8-deazahomofolic acid and its tetrahydro derivative. 312 55

Bidirectional organelle movements taking place in the cytoplasm of the rhizomes of Caulerpa, a coenocytic marine green alga, have been indicated to be dependent on microtubules (Kuroda, K. & Manabe, E. (1983) Proc. Jpn. Acad. 59B, 131-134; Manabe, E. & Kuroda, K. (1984) Proc. Jpn. Acad. 60B, 118-121). However, when a crude extract of Caulerpa rhizomes was analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and subjected to immunoblotting with monoclonal anti-tubulin antibody, no reacting band could be detected. This apparent absence of tubulin in the extract was found to be a result of the complete degradation of tubulin by potent intrinsic proteolytic activity. All of the commercially available protease inhibitors so far tested (p-chloromercuriphenylsulfonic acid, phenyl methylsulfonyl fluoride, 1-chloro-4-phenyl-3-tosylamido-2-butanone, 7-amino-1-chloro-3-tosylamido-2-heptanone, p-tosyl-L-arginine methyl ester, soybean trypsin inhibitor, antipain, chymostatin, leupeptin, and pepstatin) failed to inhibit the activity completely. But addition of casein at the concentration of 1% (weight per volume) to the solutions used for preparation was effective in protecting tubulin from proteolytic degradation, thus making it possible to prepare tubulin from the crude extract of Caulerpa. On SDS-PAGE, the Caulerpa alpha-tubulin thus prepared was a little smaller in molecular weight than that of rabbit brain.
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PMID:Preparation of tubulin from Caulerpa, a marine green alga, using casein as a protective agent against proteolytic degradation. 324 Sep 83

The hydroxynitrile lyase (EC 4.1.2.--) which catalyzes the dissociation of the cyanohydrins of acetone and 2-butanone has been isolated and purified from young seedlings of flax (Linum usitatissimum L.). The purification procedure involved precipitation with (NH4)2SO4, chromatofocusing, and chromatography on DEAE-cellulose, hydroxylapatite, Sephacryl 200, and Matrex Red A gel columns with a final recovery of 21%. Purification of 136-fold yielded an apparently homogeneous preparation that, in contrast to the lyases isolated from Prunus species, is not a flavoprotein. The subunit molecular weight of 42,000 was estimated by gel electrophoresis in the presence of sodium dodecyl sulfate. The native molecular weight of the enzyme was estimated by gel filtration (HPLC) to be 82,000. The enzyme has a narrow pH optimum around 5.5 and is highly stable at 4 degrees C.
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PMID:Purification and characterization of acetone cyanohydrin lyase from Linum usitatissimum. 337 4

The hepatotoxicity of chloroform (CHCl3) is thought to require biotransformation, by the polysubstrate monooxygenase system (P-450), to a reactive intermediate(s). Therefore, the potentiation of CHCl3-induced hepatotoxicity, which occurs following exposure to certain ketones, may hypothetically be explained by a reduced capacity of the cell to form glutathione conjugates (detoxicate the intermediate) and (or) by an increased rate of reactive intermediate(s) generation secondary to a modification of the P-450 system. To test these hypotheses, liver damage, as indicated by elevation in plasma alanine aminotransferase and ornithine carbamyl transferase activities, was modulated in male Sprague-Dawley rats by varying the time interval (10, 18, 24, 48, 72, 96 h) between acetone, 2-butanone, or 2-hexanone (15 mmol/kg, p.o.) pretreatment and CHCl3 (0.5 mL/kg, p.o.) administration. These data were compared with hepatic glutathione and with various parameters of the polysubstrate monooxygenase system: cytochrome P-450, cytochrome c reductase, cytochrome b5, and microsomal binding of 14CHCl3-derived radiolabel. Reduced detoxication capacity does not appear to be involved as hepatic glutathione levels were not reduced. Globally, a relationship between modifications to the polysubstrate monooxygenase system and potentiation of CHCl3-induced hepatotoxicity appears to exist. The rank order of each ketone's ability to modify P-450 parameters was the same in most instances as that based on peak ability to potentiate CHCl3-induced hepatotoxicity: 2-hexanone greater than 2-butanone greater than or equal to acetone. Therefore, these results suggest that a general relationship exists between the ketone-induced potentiation of CHCl3-induced hepatotoxicity and increased CHCl3 reactive metabolite generation. However, other factors may also contribute to the phenomenon.
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PMID:The role of biotransformation-detoxication in acetone-, 2-butanone-, and 2-hexanone-potentiated chloroform-induced hepatotoxicity. 344 91

L-Histidine methyl ester inactivates histidine decarboxylase in a time-dependent manner. The possibility was considered that an irreversible reaction between enzyme and inhibitor occurs [Recsei, P. A., & Snell, E. E. (1970) Biochemistry 9, 1492-1497]. We have confirmed time-dependent inactivation by histidine methyl ester and have investigated the structure of the enzyme-inhibitor complex. Upon exposure to either 8 M guanidinium chloride or 6% trichloroacetic acid, unchanged histidine methyl ester is recovered. Formation of the complex involves Schiff base formation, most likely with the active site pyruvyl residue [Huynh, Q. K., & Snell, E. E. (1986) J. Biol. Chem. 261, 4389-4394], but does not involve additional irreversible covalent interaction between inhibitor and enzyme. Complex formation is a two-step process involving rapidly reversible formation of a loose complex and essentially irreversible formation of a tight complex. For the formation of the tight complex, Ki = 80 nM and koff = 2.5 X 10(-4) min-1. Time-dependent inhibition was also observed with L-histidine ethyl ester, L-histidinamide, and DL-3-amino-4-(4-imidazolyl)-2-butanone. No inactivation was observed with glycine methyl ester or histamine. We propose that in the catalytic reaction the carboxyl group of the substrate is in a hydrophobic region. The unfavorable interaction between the carboxylate group and the hydrophobic region facilitates decarboxylation [Crosby, J., Stone, R., & Liehard, G. E. (1970) J. Am. Chem. Soc. 92, 2891-2900]. With histidine methyl ester this unfavorable interaction is no longer present; hence, there is tight binding.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Reaction of Lactobacillus histidine decarboxylase with L-histidine methyl ester. 365 38

The head space method for determination of tissue-gas partition coefficients was modified to make it suitable for determination of tissue-gas partition coefficients of water soluble solvents. The method was used to determine tissue-gas partition coefficients of acetone, 2-butanone, methanol, ethanol, 1-propanol, 2-propanol and isobutanol for six representative tissues (muscle, kidney, lung, white and gray matter of brain, and adipose tissue). Blood-gas partition coefficients and distribution between plasma and erythrocytes were also determined. Relation between tissue-blood and fat-blood partition coefficients of 35 hydrophilic and hydrophobic substances of different chemical structure is described by linear correlation equations which can be used for prediction of tissue-gas partition coefficients of any chemical for which blood-gas and fat-gas partition coefficients are known. The correlation equations are based on all currently available data.
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PMID:Determination and prediction of tissue-gas partition coefficients. 372 92

The volatile metabolites of three strains of Pseudomonas aeruginosa and one strain each of Pseudomonas cepacia, Pseudomonas maltophilia, Pseudomonas fluorescens, and Pseudomonas putida were analyzed using an automated headspace concentrator incorporating a gas chromatograph. The procedure does not require sample preparation and automates the entire analytical sequence to yield reproducible profiles of volatile constituents. Gas chromatographic profiles of the volatile metabolites of each species were obtained using a 20-min concentration period and two fused silica capillary columns of different polarities. The production of headspace metabolites from trypticase soy broth was studied in relationship to culture incubation time and initial cell concentration. The volatiles identified after 24 h incubation consisted of 1-butanol, isopentanol, toluene, 1-undecene, 2-butanone, 2-heptanone, 2-nonanone, and 2-undecanone. Sufficient amounts of specific metabolites were produced after 5 h incubation to provide information of possible diagnostic value. In particular, all P. aeruginosa strains produced a distinctive series of 1-undecene and methyl ketones after 5 h incubation of media inoculated to provide 2 X 10(6) cells/mL. The results indicate that when growth and analytical conditions are held constant, P. aeruginosa and related species produce characteristic profiles of headspace metabolites. Since conventional bacteriological tests require 24 h or more for the identification of these pseudomonads, automated volatile analysis could provide an alternative means for the rapid detection of these bacteria.
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PMID:Volatiles of Pseudomonas aeruginosa and related species by automated headspace concentration--gas chromatography. 392 82

Guinea pigs exhibited none or slight responses to sensitization with low concentrations of 2-hydroxyethylmethacrylate in the guinea pig maximization test, while 60-100% reacted to high concentrations regardless of the vehicle used for induction. Petrolatum, water, soybean oil and a mixture of oil and 2-butanone (sbomek) were used as vehicles for elicitation. The neat methacrylate was less effective than dilutions in any vehicle, petrolatum being the best. The major determinant of the frequency of response was the concentration used for intradermal induction. An increase in frequency and in duration of responsiveness after treatment with cyclophosphamide 3 days before challenge suggests that hydroxyethylmethacrylate preferentially stimulates the suppressor cell function.
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PMID:Sensitizing potential of 2-hydroxyethylmethacrylate. 401 69

The biodistribution of [14C]3,3'-(1,3-propanediyldiimino)-bis(3-methy 1-2-butanone)-dioxime, [( 14C]PnAO) was determined in anesthetized rats. The results of this study show that there is no significant brain accumulation or retention of the uncomplexed ligand in the brain.
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PMID:Biodistribution of [14C]PnAO in rats. 404 42


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